However, Lo is skeptical of the Shenzhen authorities’ suggestion that avian flu is not prevalent among local poultry stocks, and that Chen likely contracted the H5N1 virus from wild birds. “This is a poultry virus, not a wild bird virus. Blaming human infection on wild birds is not conducive to epidemic control because people might become complacent about poultry, about slaughtering sick birds. As a result, more human cases could occur,” he said.

Residents of Hong Kong and the adjacent mainland Chinese province of Guangdong, in which Shenzhen is located, have reason to feel nervous about Chen’s death.

However, the Hong Kong Center for Health Protection confirmed Tuesday that the virus strain which killed Chen is similar to the strain found in dead birds in Hong Kong last month.

“The virus found in the patient was 90 percent similar to H5N1 viruses previously isolated in ducks in China, which suggested that the man was very likely to have been infected through direct contact with a bird,” the Shenzhen Center for Disease Prevention and Control said in a statement.

“It is still not transmissible between people,” it said, adding that the bus driver was probably infected through direct contact with birds.

The virus is normally found in birds but can occasionally jump to people. Researchers worry that the virus could mutate into a form that would spread easily between humans.

Hong Kong culled 17,000 chickens at a wholesale poultry market two weeks ago after a dead chicken there tested positive for H5N1 avian virus, and suspended imports of live chickens from the mainland for 21 days in a bid to prevent any spread of the disease.